Is Bamboo Fabric Eco Friendly? Cotton vs Bamboo vs Polyester

Welcome!  At Bammbu, we’re excited about all things bamboo and specifically the environmental benefits of bamboo compared to other fabrics.  We thought it would be a good idea to write up a blog about it and hopefully give you a clearer idea of what goes into producing various types of fabrics, so here it is!

The Basics - Cotton vs Bamboo vs Polyester                                                 

Cotton needs no introduction, as it’s been used to make clothing since at least 2500 BC.  It makes up almost exactly one third of all fibres found in textiles around the world.  The mechanical production of cotton fabric produces about the normal amount of industrial waste you would expect from any sort of manufacturing.  The true environmental cost is in the farming and cultivation of the cotton crop.

Water usage is the first problem that plagues cotton cultivation.  According to the World Resource Institute, 2700 litres of water are required to make a single cotton tee shirt - equivalent to what the average human drinks over the course of 2.5 years!  The most obvious example of the devastation caused by this excessive water use can be found in Central Asia. The Aral Sea in Kazakstan and Uzbekistan used to be the 4th largest lake in the world, however in the 1960’s massive cotton plantations in the region began drawing their water from the Aral Sea for crop irrigation. The lake shrunk in size until in 1997 only 10% of the original volume of water remained.  Ban Ki-moon, the former United Nations Secretary General called the draining of the Aral Sea “one of the planets worst environmental disasters”.  

In addition to the massive fresh water requirements for cultivation, cotton plants require heavy pesticide use to survive.  According to the a report by the Environmental Justice Fund, “Cotton is the world’s most important non-food agricultural commodity, yet it is responsible for the release of US $2 billion of chemical pesticides each year, within which at least $819 million are considered toxic enough to be classified as hazardous by the World Health Organization. Cotton accounts for 16% of global insecticide releases – more than any other single crop. Almost 1.0 kilogram of hazardous pesticides is applied for every hectare under cotton”.  The effects of these toxic pesticides can be devastating to the local populations. According to the same EJF study, “In India and Uzbekistan children are directly involved in cotton pesticide application. While in Pakistan, Egypt, and Central Asia child labourers work in cotton fields either during or following the spraying season. Children are also often the first victims of pesticide poisonings, even if they do not participate in spraying, due to the proximity of their homes to cotton fields…” 

The development of organic cotton solves many of these issues.  According to Life Cycle Analysis a tee shirt made from organic cotton saves 1,430 litres of water compared to the same shirt made from traditionally grown cotton!  The benefit of organic cotton over regular cotton extends to the workers as well.  According to the website of the European Commission “71% of child labour is in agriculture. Cotton is one of the most common commodities produced with child labour and forced labour in at least 18 countries”.  Organic cotton is usually produced under the Global Organic Textile Standard or “GOTS”  seal, which guarantees that the fabric is both organic and produced by workers who are not forced into service, or child labourers.  Unfortunately organic cotton makes up less than 1 percent of all cotton produced worldwide - not nearly enough to put a dent in the cotton industry’s devastating effect on our environment and fresh water supply.  

When it comes to bamboo, although we consider it a plant bamboo is technically a member of the grass family.  Bamboo grows mainly in South/East Asia, and has been cultivated for thousands of years.  Historical uses for the bamboo canes (or stalks) include turning it into charcoal for fuel, using it as a writing surface in ancient China, including it as an ingredient in different foods, and of course bamboo was (and is still) most famously used as a construction material for thousands of years all over Asia.  In addition to its value as a material for building construction, and nowadays making clothing fabric, there is the added benefit of bamboo being able to be grown on “marginal land”, which is essentially low quality farmland which wouldn’t allow other crops to grow.

Bamboo is a regenerative plant, which means it doesn’t need to be re-planted every season, as the canes are simply chopped down and allowed to regrow.  This is much easier on the environment since large areas of earth do not need to be clear cut in order for cultivation.  Bamboo has grown naturally without irrigation for thousands of years, and requires only around 1/3 of the water that cotton crops need - and since bamboo doesn’t require pesticides to grow, there is a greatly reduced industrial burden on the surrounding areas.  Bamboo offers a secondary benefit to the environment: carbon absorption and storage.  According to a study done by the International Bamboo and Rattan Organization “living bamboo stores a similar amount of carbon to tree plantations: from around 100 to 400 tonnes of carbon per hectare”, which means that every single bamboo forest around the world is actively absorbing carbon dioxide from the air!

 The vast majority of bamboo fabric for clothing is the Rayon variety, which is why you’ll most often see garments (including ours) with labels saying “Bamboo Rayon” instead of just Bamboo.  The process for creating these bamboo fabrics starts with breaking down the tough fibres of the bamboo canes by dissolving them in Sodium Hydroxide, an alkaline solution.  This creates a pulp of bamboo cellulose, which is then washed clean of any residual chemicals (around 50% of the chemicals used in the breakdown process are recovered for reuse, while the other half get sent to “wet processing” facilities for safe treatment).  The bamboo pulp is forced through a spinneret at high pressure, creating individual strands of fibre which can then be woven into various types of bamboo fabrics.  

The resulting fabrics are extremely soft and breathable which makes them resistant to bacterial and fungal growth.  Unlike synthetic fabrics which hold onto odours and can remain smelly even after washing, bamboo fabrics are known for remaining practically odourless, even after a heavy workout!  

Because the synthetic fabrics commonly used in active wear have no natural moisture wicking capabilities, they have to be treated by various chemicals to achieve this.  These chemicals (often “hydrophilic” silicone oils) are designed to stay attached to the fibres of the fabric, and as a result many people experience allergic reactions or “textile dermatitis” due to synthetic fabrics containing these chemicals.  Bamboo doesn’t require any chemicals to achieve high levels of moisture wicking since it naturally has these characteristics in the fibres of the fabric.

 Polyester is one of the most popular fabrics for clothing, particularly fitness clothing due to its wide availability and low cost. Polyester was first invented in 1941 and brought by the chemical giant DuPont to the United States. It is a synthetically woven material that starts its life as petroleum.  After an extraction process separates a polymer (plastic) from the petroleum, it is combined with acids and cooked to form polyester, forced through a spinneret, and brought together to form strands of polyester thread.

Pictured above: Conventional value chain for polyester garments

Polyester is cheap and relatively easily made from petroleum, which lends itself to low cost clothing produced in bulk.   Despite its widespread popularity, there are common consumer complaints regarding clothes made from polyester.  The main complaint is odour retention.  According to research from the University of Alberta polyester both attracts and holds onto smelly chemical compounds longer than other fabrics.  “Polyester is a non-polar fibre-meaning it repels water - which is why it dries quickly, but that also means it naturally attracts oil from our skin, which can lead to body odour… We found that polyester isn't easily releasing those sweaty-smelling compounds, and repeated wearing puts more of them into the fibre, so over time there's this buildup of odour”.  Another issue with the fabric is the difficulty recycling it.  Once polyester is introduced into a fabric blend it becomes almost impossible to mechanically recycle the garment, which results in the vast majority of post consumer waste going straight into a landfill, or incinerated.  

The long and short of it

Cotton

Pros

• Affordable
• Widely available
• More breathable than synthetic fabrics like Polyester or Nylon

 Cons

• Massive freshwater usage required ~ 2700 Litres per tee shirt 
• Every crop must use toxic pesticides
• Child labour used in developing countries’ cotton industries

Bamboo

 Pros

• very Eco-Friendly compared to most other fabrics (requires far less water than cotton, and does not need toxic pesticides to grow)
• Bamboo forests filter carbon from the air
• Extremely soft and comfortable
• Naturally breathable - doesn’t require chemical treatments before wearing

 Cons

• chemicals are required to break down the hard stalks into soft bamboo pulp

Polyester

 Pros

• Cheap to make
• Easy to treat with chemicals for various effects (fireproofing, anti wrinkling etc.)
• Low cost allows polyester clothing to be sold cheap at high volume

 Cons       

• Requires chemical treatments in order to become breathable
• Produced from plastic that comes from fossil fuels
• Holds odours regardless of washing
• Very difficult to recycle - Vast majority ends up in landfills